This invention relates to an optical switch.
Optical fibers are commonly used in voice and data networks. Optical fibers are often bundled together in an array, each carrying a different signal of light. In certain instances the signals of light carried by the different optical fibers have to be switched from a first path to a second path, for example to work around overcrowded or broken paths. To accomplish this optical fibers are provided as inputs into and outputs from an optical switch. An apparatus for reflecting light from the input optical fibers is located in a path of light being emitted from the input optical fibers. The reflecting apparatus usually has an array of mirrors that are arranged in a manner similar to an arrangement of the input optical fibers. Each mirror reflects light from a respective input optical fiber to a selected output optical fiber.
The construction and assembly of the mirrors causes each mirror to have a range of movement about a first axis and a range of movement about a second axis transverse to the first axis. The ranges of movement must be considered when arranging the mirrors and the optical fibers.
An optical switch is provided comprising a plurality of input optical fibers, a support structure, a plurality of mirrors, and a plurality of output optical fibers. Each input optical fiber transmits a respective light signal and has an end from which the light signal is emitted. The mirrors are secured to the support structure and each mirror is located in a position wherein a respective light signal being emitted by the respective input optical fiber is reflected by the mirror. The mirror is moveable relative to the support structure for first pivotable movement about a first axis and second pivotable movement about a second axis transverse to the first axis. An angular displacement of each pivotable movement is limited by the support structure. The angular displacement of the first pivotable movement is limited more than the angular displacement of the second pivotable movement. The first axes of the mirrors extend in a first direction and the second axes of the mirrors extend in a second direction. At least 95 percent of all the mirrors are located over an area having a length in the first direction and a width in the second direction wherein the length is larger than the width. Each output optical fiber has an end through which a respective light signal reflected by a respective one of the mirrors enters the output optical fiber for transmission through the output optical fiber. Because pivoting about one axis limits pivoting about another axis, the area over which the mirrors are located has an oval shape as opposed to a rectangular shape.
Other features and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.